Optical devices inverting images are not new nor are optical devices for providing low, high or band pass filters for beam manipulation of optical spatial frequencies in the Fourier plane. Nevertheless, in many instances it is very difficult to operate on or otherwise alter the center of a beam of radiation, whether it be optically visible or otherwise, without distorting the beam. This holds true not only in the aforementioned filters for manipulation of the optical spatial frequencies in the Fourier plane but also in such fields as dark field or color contrast microscopy. To this date, although it is old to alter beams of optically visible light and to operate on the periphery of these beams, it has been difficult to reach the center of a beam of substantially parallel radiation without distorting the beam.
Radial translation in the sense of the present invention denotes a phenomenon in which the center of a beam of radiation is moved outwardly toward the periphery or perimeter of the beam and the perimeter or pheriphery of the beam is moved toward the center. The result of this new phenomenon is to concentrate intensity of a beam of substantially parallel radiation toward the center of the radially translated beam as well as to make available on the perimeter or periphery of the beam rays which were heretofore at the center of the beam.
Prior art which is pertinent in one respect or another to the present invention, copies of which are enclosed herewith include the Koester et al U.S. Pat. No. 3,670,260 directed to optical devices for altering the form and distribution of a laser beam; the Giallorenzi U.S. Pat. No. 3,743,383 directed to a system of prisms for superimposing several laser beams; the Burch et al U.S. Pat. No. 3,560,082 directed to an optical inverting system; a publication by John H. Mccleod in the August, 1954 edition of the Journal Of The Optical Society Of America, page 592, entitled "The Axicon: A New Type Of Optical Element"; a publication by John H. McCleod in the Journal Of The Optical Society Of America, volume 50, no. 2 February, 1960 entitled "Axicons And Their Uses"; a publication by Bryndahl in the Journal Of The Optical Society Of America, volume 60, no. 7 July 19, 1970 entitled "Reversed-Radial-Shearing Interferometry"; a publication by Peters and Leger in Applied Optics, volume 9, no. 6 published June, 1970, page 1435, entitled "Techniques For Matching Laser TEM Mode To Obscured Circular Aperture"; and a publication by Edmonds in Applied Optics, volume 12, no. 8 published August, 1973, page 1940, entitled "The Reflaxicon, A New Reflective Optical Element, And Some Applications."